Synthesis of Fused Heterocyclic Derivatives from 5-Ethyl-3-Hydrazino-5H-1,2,4-Triazino[5,6-b]Indole

5-Ethyl-3-hydrazino-5H-1,2,4-triazino[5,6-b ]indole II was used for the synthesis of various heterocyclic derivatives. This was performed by reaction of its 3-hydrazino group with different reagents such as acid anhydrides, ethylacetate, diethyl oxalate, thioglycolic acid, aroyl esters and acid chlorides. The structure of the products was confirmed by different spectroscopic and analytical methods

Brain-Speech Alignment Enhances Auditory Cortical Responses and Speech Perception

Asymmetry in auditory cortical oscillations could play a role in speech perception by fostering hemispheric triage of information across the two hemispheres. Due to this asymmetry, fast speech temporal modulations relevant for phonemic analysis could be best perceived by the left auditory cortex, while slower modulations conveying vocal and paralinguistic information would be better captured by the right one. It is unclear, however, whether and how early oscillation-based selection influences speech perception. Using a dichotic listening paradigm in human participants, where we provided different parts of the speech envelope to each ear, we show that word recognition is facilitated when the temporal properties of speech match the rhythmic properties of auditory cortices. We further show that the interaction between speech envelope and auditory cortices rhythms translates in their level of neural activity (as measured with fMRI). In the left auditory cortex, the neural activity level related to stimulus-brain rhythm interaction predicts speech perception facilitation. These data demonstrate that speech interacts with auditory cortical rhythms differently in right and left auditory cortex, and that in the latter, the interaction directly impacts speech perception performance

Heat Shock Protein 70 Expression in Juvenile Eastern Oysters, Crassostrea virginica (Gmelin, 1791), Exposed to Anoxic Conditions

Anoxic water events in conjunction with summer high temperatures are thought to be one of the causes of declines in natural oyster reefs on the eastern shore of Mobile Bay. Work is underway to determine whether tolerance to low oxygen can be selected for in hatchery-produced oysters. As a component of this work, the expression of heat shock protein 70 (HSP 70) was examined in control (normoxia) and anoxia-challenged juvenile oysters. Parental Eastern oysters, Crassostrea virginica were collected from 2 sites, Cedar Point Reef (CP), an area considered to have normoxic conditions, and White House Reef (WH), an area suspected to experience periodic anoxia. F1 generation oysters were produced from CP and WH parents that survived an anoxic exposure of 96 h. Control F1 generation oysters from both parental stocks not exposed to anoxia were also produced. The F1 generation oysters were subsequently exposed to anoxia or control normoxic conditions, and differences in expression of HSP 70 were examined. Nitrogen was used to create the anoxic conditions for both the parental and F1 generations. Three HSP 70 isoforms—2 constitutive forms (HSC 77 and HSC 72) and 1 inducible form (HSP 69)—were expressed in both anoxia- and normoxia-exposed oysters from all groups. Although there were differences among groups of oysters from the 2 sites, there were no differences in the expression of HSC 77 and HSC 72 between the control and anoxia-treated oysters within a group. Interestingly, the expression of HSP 69 was higher in oysters exposed to normoxia than the ones from anoxia treatments. These differences are thought to reflect a combination of responses to nutritional stress in the controls and facultative anaerobiosis and metabolic arrest in the anoxia groups

Trematodes of the Great Barrier Reef, Australia: emerging patterns of diversity and richness in coral reef fishes

The Great Barrier Reef holds the richest array of marine life found anywhere in Australia, including a diverse and fascinating parasite fauna. Members of one group, the trematodes, occur as sexually mature adult worms in almost all Great Barrier Reef bony fish species. Although the first reports of these parasites were made 100 years ago, the fauna has been studied systematically for only the last 25 years. When the fauna was last reviewed in 1994 there were 94 species known from the Great Barrier Reef and it was predicted that there might be 2,270 in total. There are now 326 species reported for the region, suggesting that we are in a much improved position to make an accurate prediction of true trematode richness. Here we review the current state of knowledge of the fauna and the ways in which our understanding of this fascinating group is changing. Our best estimate of the true richness is now a range, 1,100–1,800 species. However there remains considerable scope for even these figures to be incorrect given that fewer than one-third of the fish species of the region have been examined for trematodes. Our goal is a comprehensive characterisation of this fauna, and we outline what work needs to be done to achieve this and discuss whether this goal is practically achievable or philosophically justifiable

ZnO nanopowder derived from brass ash: Sintering behavior and mechanical properties

The present investigation studied the recycling of zinc from brass ash which is a secondary product produced during the brass smelting process. A retiring cycle was devised to produce high-purity ZnO nanopowders. Recovery of > 90 wt% of the total zinc available was achieved after the calcination of brass ash at 700 °C and a multistage hydrometallurgical treatment at room temperature. ZnO powder produced by the developed method was analyzed by X-ray diffraction, transmission electron scanning microscopy, ICP-AES and BET analysis. The ZnO nanopowder obtained from the brass ash was well dispersed and the size of the individual particles was in the range of 30–50 nm. The purity of the powder was 99.83 wt%, and the surface area was about 30.5 m2/g. A relative density level of about 98.1% was reached with ZnO pellets sintered at 1300 °C

Antibiotics Prescriptions Pattern among Patients Visiting Primary Health Care Centers (PHCC) before and during COVID-19 Pandemic: A Cross-Sectional Population-Based Study from Qatar

Background: The COVID-19 pandemic, caused by the novel coronavirus 2 (SARS-CoV-2), has been associated with an increased risk of secondary bacterial infections. Numerous studies have reported a surge in antibiotic usage during the COVID-19 pandemic. This study aims to examine the impact of the COVID-19 pandemic on the frequency and patterns of antibiotic prescriptions at Primary Health Care Centers (PHCC) in Qatar, comparing the period before and during the pandemic. Methods: This population-based, cross-sectional study analyzed all antibiotic prescriptions issued in two-month intervals before COVID-19 (November and December 2019) and during the initial wave (June and July 2020) of COVID-19. The study included 27 PHCCs in Qatar. Results: Prior to the COVID-19 outbreak, the PHCCs dispensed a total of 74,909 antibiotic prescriptions in November and December. During the first wave of COVID-19, the number decreased to 29,273 prescriptions in June and July 2020. Antibiotics were most commonly prescribed for adults and least commonly for the elderly, both before and during the COVID-19 period. In the pre-COVID-19 period, Betalactams and macrolides accounted for the majority (73%) of all antibiotic prescriptions across all age groups. However, during the COVID-19 period, Betalactams and other antibiotics such as Nitrofurantoin and Metronidazole (73%) were the most frequently prescribed. Conclusion: The rate of antibiotic prescriptions during the first wave of COVID-19 was lower compared to the two months preceding the pandemic at the PHCC in Qatar.Scopu

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia

Catalytic Transformations of Alkynes via Ruthenium Vinylidene and Allenylidene Intermediates

NOTICE: This is the peer reviewed version of the following book chapter: Varela J. A., González-Rodríguez C., Saá C. (2014). Catalytic Transformations of Alkynes via Ruthenium Vinylidene and Allenylidene Intermediates. In: Dixneuf P., Bruneau C. (eds) Ruthenium in Catalysis. Topics in Organometallic Chemistry, vol 48, pp. 237-287. Springer, Cham. [doi: 10.1007/3418_2014_81]. This article may be used for non-commercial purposes in accordance with Springer Verlag Terms and Conditions for self-archiving.Vinylidenes are high-energy tautomers of terminal alkynes and they can be stabilized by coordination with transition metals. The resulting metal-vinylidene species have interesting chemical properties that make their reactivity different to that of the free and metal π-coordinated alkynes: the carbon α to the metal is electrophilic whereas the β carbon is nucleophilic. Ruthenium is one of the most commonly used transition metals to stabilize vinylidenes and the resulting species can undergo a range of useful transformations. The most remarkable transformations are the regioselective anti-Markovnikov addition of different nucleophiles to catalytic ruthenium vinylidenes and the participation of the π system of catalytic ruthenium vinylidenes in pericyclic reactions. Ruthenium vinylidenes have also been employed as precatalysts in ring closing metathesis (RCM) or ring opening metathesis polymerization (ROMP). Allenylidenes could be considered as divalent radicals derived from allenes. In a similar way to vinylidenes, allenylidenes can be stabilized by coordination with transition metals and again ruthenium is one of the most widely used metals. Metalallenylidene complexes can be easily obtained from terminal propargylic alcohols by dehydration of the initially formed metal-hydroxyvinylidenes, in which the reactivity of these metal complexes is based on the electrophilic nature of Cα and Cγ, while Cβ is nucleophilic. Catalytic processes based on nucleophilic additions and pericyclic reactions involving the π system of ruthenium allenylidenes afford interesting new structures with high selectivity and atom economy